Lincoln.

In an instant, he knew that whatever this was, it was worth seven figures: a Lincoln signature, on a Lincoln letter, written from the Lincoln White House.

Then he looked again at the date and felt a chill: the day Lincoln was shot.

He wiped the sweat from his palms, as if he were touching the original instead of seeing it on a computer screen. He almost went looking for white cotton curatorial gloves.

Could this be Lincoln’s last letter? A last insight into the most analyzed, adulated, biographied, beloved, and, in a few places, detested man in American history? And what did this anonymous lieutenant have that mattered so much at the end of the Civil War?

Peter clicked again on the e-mail:

I held this letter in my hands a week ago, along with the envelope addressed to a Corporal Jeremiah Murphy. A man was offering it for sale to the American Museum of Emancipation. I told him we were very small, hoping to consolidate with the Smithsonian Museum of African American History and Culture when it opens in 2015, but that I would talk to our board. When I tried to contact him two days ago, he had gone incommunicado. I had been planning to ask you to appraise the letter. Would you be willing to put your skills to finding it, or at least uncovering the story behind it?

Peter lifted the wine bottle. One more tip into the glass would bring him to the bottom of the label. When he drank alone—something he’d been doing more since the wedding that wasn’t—he had a rule: Drink to the bottom of the label and no farther. Stopper the bottle. And every few nights, finish the high-quality dregs. So he poured a bit more, swirled, and sipped.

Then he wrote back:

The last big Lincoln letter to come on the market was his answer to the so-called Little People’s Petition. It went for 3.2m in ’09. That’s where the bidding starts on this, if it’s authentic. So call me. I’m up until midnight.

Then he drank the wine with a little wedge of Époisses: a big cab with a big cheese, an excellent nightcap. And NESN was nightcapping an excellent Red Sox game, which he missed because he had been working on a new exhibit for the Boston Public Library: “A Northern City and the Civil War.”

It was opening on September 22, the 150th anniversary of the day Lincoln announced the Emancipation Proclamation. The Leventhal Center was providing battle maps. Rare Books was delivering journals and photos from the famed Twentieth Regiment Collection. Peter was contributing a few things from his Antiquaria catalog, including a presentation copy of Walt Whitman’s Memoranda During the War, inscribed to Ralph Waldo Emerson. And an anonymous lender was offering a signed copy of the Emancipation Proclamation itself.

Peter was doing more than guest curators usually did. He considered it a signal honor from his city, so he wanted to earn it.

And Boston was more than his city. It was his town.

He had his roots in Southie. He’d gone to BC High and Harvard. He ran his business from the third floor of a Newbury Street bowfront that was above an art gallery that was above a restaurant. He had Red Sox season tickets and sat on the boards of two Boston museums. And he could never imagine moving to New York, no matter how much he liked to visit.

Evangeline had decided that she didn’t want to live anywhere but New York, which made marriage a problem and led them to face a hard truth: They both liked their independence, no matter how much they loved each other.

So they’d had a party instead of a wedding and settled for status quo ante. No sharing of utility bills or toothpaste, no extracurricular sharing of themselves, either.

While he waited for Diana Wilmington to call, Peter e-mailed Evangeline:

See you Sunday. We’ll have fun on the battlefields.

Then he poured the rest of the wine.

*   *   *

How did we decide that a little thing like a city would keep us apart?

That was what Evangeline Carrington was thinking as she rode a taxi down the West Side the next morning. But she didn’t think long, because she was catching the 8 A.M. Acela to Washington for her biggest professional adventure yet.

The travel writer was trying television.

She had always written—for satisfaction, for pay, for therapy.